Manufacturing variability in new designs

In a fantasy factory building an ideal product, any 2 examples of that product would be exactly the same and perform identically.
But in the real world there are variables at every step in the design and build ... so no 2 examples are 'exactly' alike.

Have the new detector designs improved repeatability between examples of the same model?
Put another way, have new designs lessened the difference between 'hot' and 'cold' examples within a model?
Differences are still there in the new machines but are they as significant as seen in older models?
As one example, think about the performance difference Tom achieved with his CZ tuning procedure. Are the latest designs still dependent on factory tuning, perhaps even manual tuning, to achieve optimal performace?

I believe with so much of the circuitry being digital, that yes...performance variances (standard deviation) have minimized significantly.

You've still got a lot of overall performance that depends on the coils fabrication/tuning, so there's still a potential bit of variability there...

But overall, yes...it's definitely better.



Edited 1 time(s). Last edit at 03/15/2018 08:06AM by Mike in CO.

A very valid concern...... and question. Mike in CO is correct. The digital units are MUCH tighter in tolerances; hence, reducing the unit-to-unit differences. Analog units can be horrific...... unit-to-unit.
For instance:
I have tested 7 AT-Pro's in a 'controlled' environment...... and all performed identically.
I have tested 6 Impacts...... all performed identically.
I have tested countless T2's and F75's....... and all were identical.
I have tested 8 CTX-3030's...... and all were identical.

There is a 'catch/stipulation'. When/If there was a difference..... (so far) every time it turned out to be the coil. Swapping coils.... would express that the unit itself... was exacting; yet, the coil may have had minor errors/differences (delta's).

Have to agree with Tom D and Mike about digital components and tolerances but just the other day a side by side comparison of two Equinox 800's on initial power up in the dark, we turned on the backlights of both machines and there was a noticeable difference between the two machines in the light intensity on each level. Something a simple as the backlight circuitry made me wonder how many other ways did the machines vary? Never did find anything else so obviously different but it makes you wonder.

Cliff

Lets not forget the nut on end of wheel...changing ground conditons across country or for that matter testers...

Mike, Tom, Cliff, thank you for the responses/observations. Tom, the results of your tests on the machines you listed is encouraging.

I did observe the last part of one manufacturer's factory test process, it did have a final tuning/performance test/check where unit and coil were paired just prior to packaging for shipment.
My background is in telecom manufacturing test and in comparison, this detector testing seemed more qualitative (less instrumented) in nature than I expected ... but that is comparing a high cost, high frequency assembly to a relatively low cost, low frequency detector.

I suppose the 'receiver' function of all detectors is still an analog circuit so that's where the adjustments and possible variance will be seen.
I have firsthand experience with this type of variance. I have an old Fisher F5 that works fine with the stock elliptical coil but will 'iron wrap' on a dollar coin when fitted with the 11" DD coil or the 5" DD coil. I believe this is a known issue with some early F5s and FTP did indicate they could fix the problem if I sent it in (maybe just tuning?).

There was also some post awhile back saying Digital can't do Modulation correctly.
I know the MX Sport can't and now the NOX doesn't do it well either.

GreenMeanie Wrote:
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> There was also some post awhile back saying Digital can't do Modulation correctly.

No, digital can do modulation probably better than analog.

Not sure thats the real question now. To me its more has the company pushed the machine to maximize its potential. ... or have they tuned it to usability? Basically so anyone can use it out of the box.

GreenMeanie Wrote:
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> There was also some post awhile back saying Digita
> l can't do Modulation correctly.
> I know the MX Sport can't and now the NOX doesn't
> do it well either.

Yes but the Etrac/Explorer can and it's adjustable, But they call it Volume Gain.
Also CTX has this feature but not as sweet sounding, to My ears anyway. Along with Fisher CZs probably the best adjustable Modulated Audio in the Business. That's One reason they are My two all-time faves.



Edited 1 time(s). Last edit at 03/15/2018 05:00PM by Harold,ILL..

Speaking of Modulation.....headphones do make a difference. You basically have to shop around for headphones that work well with your unit. Sad but True.

HH
Mike